Dual Action Spectroscopy Exposes the Bright and Dark Excitons of Room-Temperature WSe2

• DOI: 10.1021/acs.nanolett.4c06349
• Publication Date: 2025-04-04T15:55:48Z
• Authors: Joseph Wragg; Luca Bolzonello; Ludovica Donati; Karuppasamy Pandi...; Riccardo Bertini; Seth Ariel Tongay; Kenji Watanabe; Takashi Taniguchi; Frank H. L. Koppens; Niek F. van Hulst

While it has long been accepted that the role of momentum dark excitons in photoresponse transition metal dichalcogenides (TMDs) is critical, their weak optical signature inhibits study through conventional means. Here we expose room-temperature contributions both bright and to behavior a TMD, WSe2, from monolayer multilayer bulk. To do so, present dual action spectroscopy, photocurrent- luminescence-detected Fourier-transform excitation spectroscopy scheme, microscopically map energy landscape WSe2. naturally dominate luminescence response material, current response. Notably, KK' exciton more accessible than ground state KΛ, while maps reveal disparity diffusivity two states. This work provides basis for new, current-detected approach dynamics states across different materials.